Why a 10 speed transmission?

Why advertise, let alone install a 10 Speed transmission in our trucks if 10th gear is never used? Or does it take 100mph to get into 10th gear?

I watch the current gear PID and lock up status on my scan gauge 3. I have not yet to see 10th gear used yet. And converter lockup is rarely ever used. I have concluded that the advertised fuel economy will NEVER be met. Especially at 75-80mph. Even 70 gets max 21mpg on flat land.

I have confirmed the scan gauge display by manually shifting and changing gears. The dash may read 10, but the ECU displays the exact true gear I am in. This is confirmed by monitoring the tach at stead speed and zero motor speed change.

Or do I have a non working TCU???


Thanks in advance for your input,
Mike

 

You’ll rarely see 10th gear. You need 80-plus mph, no headwind, and flat or slightly downhill terrain with stock sized tires.

 

^this

especially with a low peak torque at 2,400 for a gasser, Toyota and aisin got this right

 

I’m not sure why I would rarely ever see 10th gear. What good is it to even have if it’s not going to be used? It’s like I have a 9 speed transmission with no lockup either. I was thinking I have something wrong, and feared that is my case.

Hmmmmmm

 

Nah, just drive and be happy

 

According to the Car Scanner app, my torque converter locks up all the time. Maybe have a dealer check for proper operation?

 

I've wondered this myself, it works great! I have no complaints, I've only been able to use 9 of the 10 gears but I mostly get 8. I'm pleased with it though, it's always in the right gear.

 

Coming from a 8 speed tranny in my ram this tranny is like butter and always in the correct gear.

 

My thoughts are this… the transmission seems solid and smooth for every shift. But, why have a top gear that is never used? That 10th gear may actually help us attain that 22-23mpg on the highway that is advertised. As it sure isn’t getting that anywhere. Well, maybe a flat straight 45mph road. But not at 70-80mph where highway speed limits are at all over this country.

I’m not complaining, really much more confused as to advertise something that is not used and not attainable.


Mike

 

85mph is top speed limit in U.S. (Texas). Not sure in other countries where Tundra is shipped. Will it go into 10th gear at 85-90??

 

Not hard to achieve that mileage at all. I could go on a drive at this very minute and get that. The transmission is a really fine piece of engineering, design, and execution.

 

For the same reason if it was an 8 speed you would probably be on here complaining it should be a 10 speed.

Enjoy life....if one of these is in your driveway you are doing pretty good

 

I’m actually thinking it should be a 12 speed, so we actually would get the 10 advertised.


Mike

 

My point exactly ......why only 10 when I buy a 12 LOL

 

The 10 speed will probably let it roll down hills not using the engine back pressure. My ram was notorious for down shifting than reving high going down hills.

 

There was a forum member a while ago who said it did at those speeds. Might have been in that big tranny cooler thread but not positive. I tried to make it happen once but traffic wouldn't allow a sustained 85.

 

10 spd is perfect compared to the Toyota 6spd I came from. That 6spd mother was a shifting spaz - never happy and mpg was nothing to brag about. Perfectly happy with my 10spd Tundra.

 

Toyota’s manual mode is more of a gear limiter. The number it displays is the highest gear you’re saying the truck can shift into if it wants to.

 

I donna know!!! Driving back from New Mexico to Dallas. The wife made it over 90 when it was her turn to drive. I will say it's nice to still have more to climb in gear after 70. Even with the Stillen. Is it better when in 4 Hi?

My old 2018 ecoboost was a turd on the highway.

 

According to a post on here 9th gear ratio is a 0.66 ovedrive and 10th is a 0.61. I don't think it'd make that much of a difference anyways.

 

That's the only reason that makes sense to me.

 

So my question is...
Are their any PIDs for the Torque or OBD Fusion apps for the tranny that will show more info than the pre programmed ones?

 

Not sure about Torque, but last time I checked with OBD Fusion they did not have PIDs for the Gen 3. I've been using the Car Scanner app and their PIDs for 2016-Present are working for me.

 

10th is a pain to get to, but does help with mpg if driving at 78-80 mph or so. I use cruise control most the time on the interstate, and setting it around 80 tends to run at higher rpm and takes a hit on the mpg. I've found that getting up to 85+, setting cc, then backing down the set speed to 78-80 will keep you in that higher gear and help fuel economy. You won't see the mpg like you would cruising around 55-60, but it's an improvement.

 

Mine will shift into 10th at around 78-80mph. At least it did when stock. I just put on some mild AT’s in 275/60’s (half inch taller than stock) and my MPG definitely took a hit. Went from 21-22 Hwy at around 70-72mph to barely breaking 17mpg at 70.

 

Sorry but not getting 22-23mpg on the highway isn't gotten anywhere? My 2023 Limited 4x4 routinely clocks 24mpg at 65-75 mph on 3 hour trips from CT into ME. There are really good explanations of when 10th gear is used in the posts above.

 

recent trip on interstate....

Im not a MPG guy, I like to boost, but I was pretty impressed cruising along longer trips.

winter blend most likely also

 

This is kinda of like complaining that you're not in 1st gear all the time. If it's not in that gear then the way you are driving it wouldn't be optimal. Would you rather it used it all the time but ran like crap as a result? Go drive a 3rd gen Tacoma. It has 6 gears, and it will use 4 of them multiple times just to go up a hill.


Now that I have the snark out of the way, the legit reason you're not seeing it is because it's going to be a really eco oriented gear for very low load situations. You're more likely to be in it cruising around at speeds between 45 and 65 than you are on the interstates. As I understand it, the EPA Highway testing and MPG rating is for 60-65 MPH on flat ground with no wind, not for interstate speeds in the real world. So, in truth, the why of it is because of regulations that target that speed range for optimal efficiency/emissions so manufacturers HAVE to target that range for best efficiency. Test it out. Find a flat patch of road that you can run 60 MPH on and see what gear it uses.